# Plot polygons and deforestation checks: audit-ready geolocation data > Farmer1st's geo service captures plot polygons by walking the boundary with GPS, validates every geometry for errors and overlaps, and assesses deforestation and protected areas up to today against EU-recognised forest baselines. You choose the calculation method: ours, a public reference such as Whisp (FAO), or your own risk model. ## What it does - **Boundary walking, offline** — Field agents or farmers walk the plot boundary with GPS, with or without a network, and see the polygon take shape as they go. - **Geometry validation** — Self-intersections, overlaps between neighbouring plots, implausible areas and points used where a polygon is needed are caught before submission. - **Deforestation up to today** — Multi-source assessment against the 31 December 2020 cut-off and EU-recognised forest baselines, refreshed over time rather than frozen at one year. - **Protected-area checks** — Each plot is checked against protected and conservation areas, with the result recorded next to the deforestation assessment. - **Your calculation method** — Apply our method, a public reference such as Whisp (FAO), or a custom model that follows your own thresholds, sources and treatments. ## How it works 1. **Capture or import** — Walk the boundary in the field app, or import existing polygons and points as GeoJSON, KML, Shapefile or CSV. 2. **Validate the geometry** — Every shape is checked and repaired where safe; the rest is flagged with a clear reason and sent back for re-collection. 3. **Assess the plot** — Deforestation and protected-area checks run with the method your risk policy specifies, plot by plot. 4. **Use the result** — Plot-level risk signals feed your due diligence, your DDS and your supplier decisions, with every version kept. ## What you get - Audit-ready geolocation data - Fewer polygons rejected downstream - Plot-level risk signals you can explain - A risk method that matches your policy ## Why does plot geolocation matter so much? The [EUDR](/glossary/eudr/) asks for the [geolocation](/glossary/geolocation/) of every plot of land where a relevant commodity was produced. Plots of more than 4 hectares must be described with a [polygon](/glossary/polygon/); smaller plots may be described with a single point. Everything else in due diligence depends on this data: if the plot is wrong, the deforestation assessment is wrong, and so is the [due diligence statement](/glossary/due-diligence-statement/). For smallholder supply chains, geolocation is often the weakest link. Boundaries are sketched from memory, recorded on a phone with poor signal, or collected twice by two buyers who get two different answers. ## How are polygons captured in the field? Field agents or farmers walk the boundary of the plot with the GPS of their phone. The app works offline, shows the shape as it forms, and warns when something looks wrong, for example a boundary that crosses itself or an area far from what the farmer declared. The polygon is linked to the farmer and to their consent from the moment it is recorded, and it syncs when a connection is available. Collection campaigns are organised through [field agent management](/services/field-agent-management/): which villages, which plots, which agent, and which plots need a second visit. ## What does geometry validation check? Every polygon and point, whether captured in our app or imported through [data integration](/services/data-integration/), goes through the same checks: - **Self-intersection:** boundaries that cross themselves. - **Overlaps:** plots that overlap their neighbours or duplicate another record. - **Area sanity:** areas that are implausibly small or large, or far from the declared size. - **Points versus polygons:** points used where the plot size calls for a polygon. - **Location sanity:** plots outside the expected country or region, or on water or roads. Safe corrections are applied automatically and recorded. Everything else is flagged with a plain reason and can be sent back to the field as a mission. ## How do you assess deforestation up to today? Each plot is assessed against the 31 December 2020 cut-off date using multiple sources and EU-recognised forest baselines. The assessment covers the period from the cut-off up to today, and it can be refreshed over time, so a change on the land after the first check is still caught. Plots are also checked against protected and conservation areas. The result is a plot-level risk signal: a clear status, the evidence behind it, and the method used. This is what makes a plot [deforestation-free](/glossary/deforestation-free/) in a way you can explain to an auditor. ## Whose calculation method is used? Yours. Different companies have different risk policies, and a single imposed method rarely fits all of them. You can choose: | Option | When it fits | |---|---| | Our method | You want a ready, documented approach | | A public reference method, such as Whisp (FAO) | You want a method recognised outside your company | | A custom risk model | Your policy sets its own sources, thresholds and treatment of edge cases | The method is stored with every result, so you can show which rules produced which decision. ## Where do the results go? Plot-level results feed directly into [EUDR compliance](/services/eudr-compliance/), where they become part of the due diligence report and the DDS. They can also support [trees and agroforestry](/services/trees-agroforestry/) programmes, carbon projects and your own supplier decisions. Every version of every polygon is kept, so a correction never erases what was known before. Read more about the regulation in our [EUDR guide](/guides/eudr/). ## Can we get a geo service built around our needs? Yes. Modules switch on as you need them, and anything missing, such as a specific risk model, an extra spatial layer or a custom report, we prototype with you in the [Nursery](/nursery/). ## Frequently asked questions ### When is a polygon required instead of a single GPS point? Under the EUDR, plots of land of more than 4 hectares must be described with a polygon, while smaller plots may be described with a single point. A polygon gives a much stronger basis for a deforestation assessment, so many companies collect polygons for smaller plots too. ### Why do our polygons keep failing validation? The most common causes are self-intersecting boundaries, overlaps with neighbouring plots, areas that do not match the declared size, too few vertices, and points recorded where a polygon was expected. Our validation catches each of these, repairs what can be repaired safely and sends the rest back to the field with the reason. ### Can we use Whisp or our own deforestation method? Yes. You can apply our own method, a public reference method such as Whisp from FAO, or a custom risk model that follows your policy: which sources count, what thresholds apply, how edge cases are treated. The method used is recorded with each result. ### Is deforestation assessed only against 2020 imagery? No. The EUDR cut-off date is 31 December 2020, but we assess what has happened on each plot from that date up to today, using multiple sources. A plot that was compliant at the first check can be flagged later if the land changes. ### Can we import polygons collected with other tools? Yes. We accept GeoJSON, KML, Shapefile and CSV from any field tool or vendor, validate them the same way as polygons captured in our app, and keep the original version alongside any correction.